[PATCH 1/3] remoteproc: core: Move cdev add before device add

From: Siddharth Gupta
Date: Mon May 17 2021 - 16:46:18 EST


When cdev_add is called after device_add has been called there is no
way for the userspace to know about the addition of a cdev as cdev_add
itself doesn't trigger a uevent notification, or for the kernel to
know about the change to devt. This results in two problems:
- mknod is never called for the cdev and hence no cdev appears on
devtmpfs.
- sysfs links to the new cdev are not established.

The cdev needs to be added and devt assigned before device_add() is
called in order for the relevant sysfs and devtmpfs entries to be
created and the uevent to be properly populated.

Signed-off-by: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>
---
drivers/remoteproc/remoteproc_core.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
index 626a6b90f..562355a 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -2316,6 +2316,11 @@ int rproc_add(struct rproc *rproc)
struct device *dev = &rproc->dev;
int ret;

+ /* add char device for this remoteproc */
+ ret = rproc_char_device_add(rproc);
+ if (ret < 0)
+ return ret;
+
ret = device_add(dev);
if (ret < 0)
return ret;
@@ -2329,11 +2334,6 @@ int rproc_add(struct rproc *rproc)
/* create debugfs entries */
rproc_create_debug_dir(rproc);

- /* add char device for this remoteproc */
- ret = rproc_char_device_add(rproc);
- if (ret < 0)
- return ret;
-
/* if rproc is marked always-on, request it to boot */
if (rproc->auto_boot) {
ret = rproc_trigger_auto_boot(rproc);
--
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